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An efficient and regioselective synthesis of acyclic C-nucleosides from mesoionic compounds
Carbohydrate Research, 186 (1989) ~74~8 Elsevier Science Publishers B.V., Amsterdam
c7 - Printed
in The Netherlands
Preliminary communication
An efficient and regioselective compounds
synthesis of acyclic C-nucleosides
from mesoionic
MARTINAVALOS, REYESBAESIANO, INOCENTEBAUTISTA,JUAN I. FERNANDEZ,JOSEL. JIMENEZ*,JUAN C. PALACIOS,JOAQUINPLUMET,AND FRANCISCAREBOLLEDO Department of Organic Chemistry, University of Extremadura, 06071 Badajoz (Spain) (Received
August
27th, 1988; accepted
for publication,
December
17th, 1988)
During the past few decades, much effort has been directed toward the development of synthesis routes to C-nucleosides, and 1,3-dipolar cycloadditions to carbohydrate dipolarophiles constitute an easy and versatile pathway1-3. Although data on the reactivity of mesoionic heterocycles4-7 are abundant, to our knowledge, there has been no report on cycloadditions with sugar electron-attracting olefins and we now report on this topic. 3-Methyl-2-(4-nitrophenyl)-4-phenyl-l,3-oxazolium-5-olate8 reacted (1) regioselectively with (E)-3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-l-C-nitro-~-galacto(2) and -D-manno-hept-l-enitolg (3) (acetic anhydride, 7 days, room temp.) to give the pyrrole derivatives 4+ (69%; m.p. SO-152”, [o]o -78” (c 0.5, chloroform)} and 5 (65%; m.p. 84-86”, [aID +53” (c 0.5, chloroform)}, respectively, presumably via 6 which loses carbon dioxide and nitrous acidlo, and aromatises. The structures of 4 and 5 were established through the selective irradiation of phenyl protons and subsequent magnetisation transfer to H-4 (-12%). Explanation of the regiochemical course of this reaction requires further study. Deacylation of 4 and 5 with methanolic sodium methoxide gave the acyclic C-nucleosides 1-methyl-Z(4-nitrophenyl)-3-(D-g&c&+ (6) (66%; m.p. 168-170”, [c& -67” (c 0.5, pyridine)} and 3-(D-munno-pentitol-1-yl)-Sphenylpyrrole (7) (73%; m.p. 98-100” (dec.), [&, -53” (c 0.5, ethanol)}, respectively, and the oxidative degradation of the pentahydroxypentyl chain of these compounds yielded the 3-formyl derivative 8, m.p. 148-149” (from ethanol). The structures assigned to 4-8 accord with the spectral data (u.v., i.r., ‘Hand r3C-n.m.r.). The above C-3 pyrrole nucleosides, now available from accessible mesoionic compounds, were obtained” previously by reaction of l-alkyl(aryl)amino-l-deoxy*Author for correspondence. ‘Satisfactory elemental analyses 0008-6215/89/$03.50
were obtained
@ 1989 Elsevier
for 4-7. Science Publishers
B.V.
PRELIMlNARY
c8 D-fructoses with 1,3-dicarbonyl compounds. procedure are being studied further.
H,d=
The scope and limitations
of the new
I OAC
6
R =
Pcracetylated sugar
OAC,RZc=
COMMUNICATION
H
CHZOAC
cnain
4R’ = H,R2Z OAr 5w’=
SN02
OAc.R*=
H
&No> ‘IOCH
6R’=
H,R’=
OH
7 R1= OH,R2 = H
ACKNOWLEDGMENT
This research was supported y TCcnica (Grant No. PB86-0255).
by Direccidn
General
de Investigaci6n
Cientifica
REFERENCES 1 H. P. ALBRECHT, D. B. REPKE, AND J. G. MOFFATI‘, J. Org. Chem., 40 (1975) 2143-2147. 2 J. G. BUCHANAN, A. R. EDGAR, M. J. POWER, AND G. C. WILLIAMS, Carhohydr. Kes., 55 (1977) 225-238. F. G. DELAS HERAS, S. Y.-K. TAM, R. S. KLEIN, AND J. J. Fox, .I. Org. Chem., 41 (1976) 84-90. W. D. OLLIS AND C. A. RAMSDEN, Adv. Heterocycl. Chem., 19 (1976) l-122. C. G. NEURON AND C. A. RAMSDEN, Tetrahedron, 38 (1982) 2967-3011. W. D. OLLIS, S. P. STANFORTH, AND C. A. RAMSDEN, Tetrahedron, 41 (1985) 2239-2329. K. T. Po-rrs, in A. PADWA (Ed.), I,3-Dipolar Cycloaddition Chemistry, Vol. 2, Wiley, New York, 1984. pp. l-82. 8 H. 0. BAYER, R. HUISGEN, R. KNORR, AND F. C. SCHAEFER, Chem. Ber., 103 (1970) 2581-2597. 9 J. C. SOWDEN AND D. R. STROBACH, J. Am. Chem. Sot., 82 (1960) 954-955. 10 W. E. PARHAMAND J. L. BLEASDALE, .I. Am. Gem. SW., 72 (1950) 3843-3846. 11 F. GARCIA GONZALEZ, J. FERNANDEZ-BOLA~~OS,AND F. J. LOPEZ APARICIO, ACS. Symp. Ser., 39 (1976) 207-226.
c7 - Printed
in The Netherlands
Preliminary communication
An efficient and regioselective compounds
synthesis of acyclic C-nucleosides
from mesoionic
MARTINAVALOS, REYESBAESIANO, INOCENTEBAUTISTA,JUAN I. FERNANDEZ,JOSEL. JIMENEZ*,JUAN C. PALACIOS,JOAQUINPLUMET,AND FRANCISCAREBOLLEDO Department of Organic Chemistry, University of Extremadura, 06071 Badajoz (Spain) (Received
August
27th, 1988; accepted
for publication,
December
17th, 1988)
During the past few decades, much effort has been directed toward the development of synthesis routes to C-nucleosides, and 1,3-dipolar cycloadditions to carbohydrate dipolarophiles constitute an easy and versatile pathway1-3. Although data on the reactivity of mesoionic heterocycles4-7 are abundant, to our knowledge, there has been no report on cycloadditions with sugar electron-attracting olefins and we now report on this topic. 3-Methyl-2-(4-nitrophenyl)-4-phenyl-l,3-oxazolium-5-olate8 reacted (1) regioselectively with (E)-3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-l-C-nitro-~-galacto(2) and -D-manno-hept-l-enitolg (3) (acetic anhydride, 7 days, room temp.) to give the pyrrole derivatives 4+ (69%; m.p. SO-152”, [o]o -78” (c 0.5, chloroform)} and 5 (65%; m.p. 84-86”, [aID +53” (c 0.5, chloroform)}, respectively, presumably via 6 which loses carbon dioxide and nitrous acidlo, and aromatises. The structures of 4 and 5 were established through the selective irradiation of phenyl protons and subsequent magnetisation transfer to H-4 (-12%). Explanation of the regiochemical course of this reaction requires further study. Deacylation of 4 and 5 with methanolic sodium methoxide gave the acyclic C-nucleosides 1-methyl-Z(4-nitrophenyl)-3-(D-g&c&+ (6) (66%; m.p. 168-170”, [c& -67” (c 0.5, pyridine)} and 3-(D-munno-pentitol-1-yl)-Sphenylpyrrole (7) (73%; m.p. 98-100” (dec.), [&, -53” (c 0.5, ethanol)}, respectively, and the oxidative degradation of the pentahydroxypentyl chain of these compounds yielded the 3-formyl derivative 8, m.p. 148-149” (from ethanol). The structures assigned to 4-8 accord with the spectral data (u.v., i.r., ‘Hand r3C-n.m.r.). The above C-3 pyrrole nucleosides, now available from accessible mesoionic compounds, were obtained” previously by reaction of l-alkyl(aryl)amino-l-deoxy*Author for correspondence. ‘Satisfactory elemental analyses 0008-6215/89/$03.50
were obtained
@ 1989 Elsevier
for 4-7. Science Publishers
B.V.
PRELIMlNARY
c8 D-fructoses with 1,3-dicarbonyl compounds. procedure are being studied further.
H,d=
The scope and limitations
of the new
I OAC
6
R =
Pcracetylated sugar
OAC,RZc=
COMMUNICATION
H
CHZOAC
cnain
4R’ = H,R2Z OAr 5w’=
SN02
OAc.R*=
H
&No> ‘IOCH
6R’=
H,R’=
OH
7 R1= OH,R2 = H
ACKNOWLEDGMENT
This research was supported y TCcnica (Grant No. PB86-0255).
by Direccidn
General
de Investigaci6n
Cientifica
REFERENCES 1 H. P. ALBRECHT, D. B. REPKE, AND J. G. MOFFATI‘, J. Org. Chem., 40 (1975) 2143-2147. 2 J. G. BUCHANAN, A. R. EDGAR, M. J. POWER, AND G. C. WILLIAMS, Carhohydr. Kes., 55 (1977) 225-238. F. G. DELAS HERAS, S. Y.-K. TAM, R. S. KLEIN, AND J. J. Fox, .I. Org. Chem., 41 (1976) 84-90. W. D. OLLIS AND C. A. RAMSDEN, Adv. Heterocycl. Chem., 19 (1976) l-122. C. G. NEURON AND C. A. RAMSDEN, Tetrahedron, 38 (1982) 2967-3011. W. D. OLLIS, S. P. STANFORTH, AND C. A. RAMSDEN, Tetrahedron, 41 (1985) 2239-2329. K. T. Po-rrs, in A. PADWA (Ed.), I,3-Dipolar Cycloaddition Chemistry, Vol. 2, Wiley, New York, 1984. pp. l-82. 8 H. 0. BAYER, R. HUISGEN, R. KNORR, AND F. C. SCHAEFER, Chem. Ber., 103 (1970) 2581-2597. 9 J. C. SOWDEN AND D. R. STROBACH, J. Am. Chem. Sot., 82 (1960) 954-955. 10 W. E. PARHAMAND J. L. BLEASDALE, .I. Am. Gem. SW., 72 (1950) 3843-3846. 11 F. GARCIA GONZALEZ, J. FERNANDEZ-BOLA~~OS,AND F. J. LOPEZ APARICIO, ACS. Symp. Ser., 39 (1976) 207-226.